CN103954892B - Transformer bushing voltage-sharing device suitable for conducting rods with various sizes - Google Patents

Abstract

The invention discloses a voltage equalizing device for transformer bushings suitable for conductive rods of various sizes, which includes a voltage equalizing ring and connecting fittings. The ring and the lower ring are divided into upper and lower layers and are parallel to each other. The upper ring and the lower ring are connected by a connecting bracket. The connecting bracket includes a vertical rod and a horizontal rod. In the middle of the vertical rod, the vertical rod and the horizontal rod are distributed along the center line of the pressure equalizing ring, the inner end of the horizontal rod extends inward, and the end of the horizontal rod is provided with a first connecting hole; the connecting hardware includes a sleeve and The connecting rod is set horizontally, and the sleeve is cylindrical; for the conductive rod at the end of the transformer bushing of different sizes, only one pressure equalizing ring is needed, and by adjusting the appropriate size of the fitting or adjusting the relative position of the fitting and the voltage equalizing ring, A good pressure equalization effect can be achieved.

Description

A Transformer Bushing Pressure Equalizing Device Applicable to Conductive Rods of Various Sizes

technical field

The invention relates to the field of super/ultra-high voltage transformers, in particular to a voltage equalizing device for valve-side bushings of a converter transformer during a partial discharge test of a ±800kV direct-current ultra-high voltage converter transformer.

Background technique

The equalizing ring used in high-voltage electrical appliances, high-voltage test equipment, and power systems (high-voltage lines, substations, etc.) belongs to high-voltage electrical accessories, and can also be understood as one of the power fittings. There are two types of shielding rings and voltage equalizing shielding rings with names similar to those of the voltage equalizing ring. The main function of the voltage equalizing ring is to equalize the voltage. It is suitable for the form of AC voltage. It can evenly distribute the high voltage around the object to ensure that there is no potential difference between the various parts of the ring, so as to achieve the effect of voltage equalization.

Voltage equalizing rings can be divided into lightning arrester voltage equalizing rings, lightning protection voltage equalizing rings, insulator voltage equalizing rings, transformer voltage equalizing rings, high voltage test equipment voltage equalizing rings, power transmission and transformation line voltage equalizing rings, etc. according to different uses. According to different materials, the pressure equalizing ring can be divided into aluminum pressure equalizing ring, stainless steel pressure equalizing ring, iron pressure equalizing ring and so on.

At present, the grading rings used in high-voltage electrical appliances and power systems (substations, high-voltage lines, etc.) in China are mainly made of aluminum alloy. Generally, the surface of the grading ring is required to be polished to achieve a smooth surface without burrs.

When conducting partial discharge tests on electrical equipment, in order to avoid interference with partial discharge measurements, a pressure equalizing ring should be installed on the pressure side of the tested product, and the maximum field strength E _max on the surface of the pressure equalizing ring should be controlled to prevent it from fainting .

Contents of the invention

The purpose of the present invention is to provide a voltage equalizing device for transformer bushings suitable for conductive rods of various sizes, which can utilize the voltage equalizing ring to the greatest extent.

Technical scheme of the present invention is:

A voltage equalizing device for transformer bushings suitable for conductive rods of various sizes, including a voltage equalizing ring and connecting fittings. It is divided into upper and lower layers and parallel to each other. The upper ring and the lower ring are connected by a connecting bracket. The connecting bracket includes a vertical bar and a horizontal bar. The vertical bar is set vertically, and the horizontal bar is set horizontally. In the middle, the vertical bar and the horizontal bar are distributed along the center line of the pressure equalizing ring, the inner end of the horizontal bar extends inward, and the end of the horizontal bar is provided with a first connecting hole; the connecting fittings include a sleeve and a horizontally arranged connection Rod, the sleeve is cylindrical; one end of the connecting rod is fixedly connected to the outer surface of the sleeve, the other end of the connecting rod is provided with a second connecting hole, the first connecting hole of a single cross bar and the single connecting rod The position of the second connection hole is corresponding; the corresponding crossbar coincides with the center line of the connection rod; the first connection hole and the second connection hole are connected by bolts.

A long bolt is also connected between the first connecting hole and the second connecting hole, the long bolt is arranged vertically, the two ends of the long bolt are detachably connected with the first connecting hole and the second connecting hole respectively, and the long bolt The length is suitable for the length of the conductive rod at the end of the transformer bushing to be connected.

There are four cross bars and connecting rods, which are evenly arranged along the circumferential direction.

The inner diameter of the sleeve is adapted to the outer diameter of the conductive rod at the end of the transformer bushing to be connected.

Advantages of the present invention:

First, the equalizing ring has strong adaptability. For different sizes of conductive rods at the ends of transformer bushings, only one voltage equalizing ring is required, and a good voltage equalizing effect can be achieved by adjusting the appropriate size of the fitting or adjusting the relative position of the fitting and the voltage equalizing ring;

Second, the voltage equalizing ring is easy to use, and the connecting hardware in the present invention only needs to be set on the conductive rod of the transformer bushing to be firmly fixed during installation, without other cumbersome fixing methods;

Third, the pressure equalizing ring is light in weight and convenient in transportation; low in cost and high in cost performance.

The present invention realizes that only one size of pressure equalizing ring can be used to solve the problem of different sizes of transformer bushings in the test process by adopting the free combination of several different sizes of connecting fittings, one pressure equalizing ring and four fully threaded screws. Pressure equalization in pipe conduction rod tests. It can effectively suppress the corona discharge interference in the high-voltage test process, and is suitable for the interference suppression of the corona discharge of transformer bushings with different sizes of conductive rods.

Description of drawings

Fig. 1 is a structural representation of the pressure equalizing ring of the present invention;

Fig. 2 is the top view of Fig. 1;

Fig. 3 is a structural schematic diagram of connecting fittings;

Fig. 4 is the top view of Fig. 3;

Fig. 5 is a schematic diagram of the state of use;

Figure 6 is a schematic structural view of the tested transformer bushing conductive rod when the length is relatively long;

Fig. 7 is a schematic diagram of the structure when the length of the conductive rod of the transformer bushing under test is short.

detailed description

As shown in Fig. 5, the present invention includes a pressure equalizing ring 1 and a connecting fitting 2. As shown in Fig. Both are circular rings with the lower ring 4, the diameters of the two are the same, the centerlines of the two coincide and the two are parallel to each other. The connecting bracket 5 includes four vertical vertical rods 5-1 arranged in the circumferential direction, the middle part of each vertical rod is fixedly connected with a cross bar 5-2, and the cross rod 5-2 extends inwardly, and the four cross rods 5- 2 Make a circular distribution around the center line of the pressure equalizing ring 1. A first connection hole 5-3 for bolt connection is provided at the end of the cross bar 5-2 near the inner end.

As shown in Figures 3 and 4, the connecting fitting 2 includes a sleeve 2-1 and a connecting rod 2-2 fixedly connected to the outer circumferential surface of the sleeve 2-1. There are four connecting rods 2-2 in total. -1 The outer peripheral surface is uniformly arranged. The outer end of the connecting rod 2-2 is provided with a second connecting hole 2-3. The position of the connecting rod 2-2 corresponds to the position of the adjacent cross bar 5-2, that is, the center line of the connecting rod 2-2 coincides with the adjacent cross bar 5-2, and the first connecting hole 5-3 and the adjacent cross bar 5-2 coincide. The second connection holes 2-3 correspond to the bolts 6 for installation.

The inner diameter D of the sleeve 2-1 can be made into several specifications according to the needs, and the sleeve 2-1 with different inner diameters can be used according to the different diameters of the conductive rod 7 of the tested transformer bushing.

As shown in Figure 5, due to the different currents of the converter transformers, the diameter of the conductive rod 7 at the end of the bushing of the tested transformer will vary from large to small. When the diameter d of the conductive rod 7 at the end of the bushing changes, the diameter d The dimensions match d for easy installation. This device makes three kinds of fittings with different diameters D. When the diameter of the conductive rod 7 is thick, we install fittings with a larger diameter. When the diameter of the conductive rod 7 is thin, we install fittings with a thinner diameter. This installation always ensures equal pressure. The center of the end face of the ring coincides with the center of the end face of the conductive rod 7 of the transformer bushing under test, thereby maximizing the effect of voltage equalization.

As shown in Figures 6 and 7, because the extension length of the conductive rod 7 is different, the length of the conductive rod 7 at the end of the tested transformer bushing will be very large due to the large contact area required when the wire is connected to the conductive rod in design. Long, when the length L of the conductive rod 7 at the end of the bushing changes, add four full-threaded screws with the same length between the pressure equalizing ring 1 and the connecting fitting 2, and then the distance between the connecting fitting and the center of the pressure equalizing ring will change, thereby smoothly Install the equalizing ring. When the conductive rod 7 is very long, a screw is installed between the pressure equalizing ring 1 and the connecting fitting 2 to make the connecting fitting 2 translate in a direction away from the end of the casing, thus avoiding the installation of the conductive rod end due to the too long conductive rod 7. It protrudes outside the pressure equalizing surface of the equalizing ring, resulting in the effect that the tip cannot reach the equalizing pressure.

Therefore, the present invention also includes four long rod bolts 8, the long rod bolts 8 are fully threaded bolts, and the upper and lower ends of the long rod bolts 8 are respectively connected with the first connecting hole 5-3 and the second connecting hole 2-3 through nuts. , the length of the long rod bolt 8 between the first connection hole 5-3 and the second connection hole 2-3 can be adjusted appropriately, so that the positional relationship between the conductive rod 7, the transformer bushing and the upper ring 3 or lower ring 4 satisfies Electrical installation requirements. The purpose of the lowest field intensity at the end of the bushing and the best shielding effect of the equalizing ring is achieved.

For the convenience of adjustment, the first connection hole 5-3 or the second connection hole 2-3 can be made into a long hole, or both can be made into a long hole, which is convenient for assembly.

To sum up, the overall structure of the present invention is simple and ingenious, which can effectively improve the utilization rate of the pressure equalizing ring and thus greatly improve the working efficiency on site.

Claims (4)

1. a kind of bushing shell for transformer pressure-equalizing device being applied to various sizes conducting rod it is characterised in that：Including grading ring and company Connect gold utensil, grading ring is twin nuclei, and grading ring includes upper ring and lower ring and connecting bracket, upper ring and lower ring be divided into upper and lower two-layer and It is parallel to each other, is connected by connecting bracket between upper ring and lower ring, connecting bracket includes vertical rod and cross bar, vertical rod is vertically arranged, horizontal Bar is horizontally disposed with and outer one end is fixedly connected on middle part, vertical rod and cross bar edge all centered on the centrage of grading ring of vertical rod Circumferencial direction is distributed, and inner one end of cross bar extends internally, and the end of the inner one end of cross bar is provided with the first connecting hole；Connection gold utensil Including sleeve and horizontally disposed connecting rod, sleeve is cylindrical shape；One end of connecting rod is fixedly connected on the periphery of sleeve, The other end of connecting rod is provided with the second connecting hole, the second connection hole site of the first connecting hole of single rail and single connecting rod Corresponding；Corresponding cross bar is overlapped with the centrage of connecting rod；It is bolted between first connecting hole and the second connecting hole.

2. the bushing shell for transformer pressure-equalizing device being applied to various sizes conducting rod according to claim 1 it is characterised in that： It is also associated with bolt of long stem, bolt of long stem is vertically arranged, bolt of long stem two ends between described first connecting hole and the second connecting hole It is detachably connected with the second connecting hole with the first connecting hole respectively, the length of bolt of long stem and tested bushing shell for transformer to be connected The length of termination conducting rod is adapted.

3. the bushing shell for transformer pressure-equalizing device being applied to various sizes conducting rod according to claim 1 and 2, its feature exists In：Cross bar and connecting rod all have four, and four connecting rods are all along the circumferential direction uniformly arranged.

4. the bushing shell for transformer pressure-equalizing device being applied to various sizes conducting rod according to claim 1 and 2, its feature exists In：The internal diameter of sleeve is adapted with the external diameter of tested transformer sleeve pipe end conducting rod to be connected.